Sweat-Powered Wearable Revolutionizes Health Monitoring
A new sweat-powered wearable will transform health monitoring, making it as easy as wearing a Band-Aid. Engineers have developed a device that uses sweat from the fingertip to monitor vital health markers continuously. This breakthrough simplifies health tracking and makes it accessible anytime. Engineers from the University of California San Diego have developed an electronic finger wrap that continuously monitors vital chemical levels—such as glucose, vitamins, and even drugs—using the sweat from the fingertip to power the device. On September 3, Joseph Wang’s research group from the Aiiso Yufeng Li Family Department of Chemical and Nano Engineering at UC San Diego published this breakthrough in *Nature Electronics*.
Innovative Design and Energy Source
The wearable, designed to fit snugly around the finger, draws power from an unexpected source: the fingertip’s sweat. Fingertips, rich in sweat glands, produce significantly more sweat than most other body areas, even at rest. This steady flow of perspiration provides a reliable energy source for the device, enabling it to function even when the wearer is inactive or sleeping.
Flexible and Durable Construction
The device is crafted from a thin, flexible, and stretchable polymer material with printed electronic components. It adapts to the finger’s shape while being durable enough to endure bending, stretching, and movement. “The device integrates energy harvesting and storage components with biosensors and an electronic controller, all at the fingertip,” explained Wang.
Advanced Biofuel Cells and Sensors
At its core are biofuel cells that convert chemicals in sweat into electricity. This electricity is stored in stretchable silver chloride-zinc batteries, which power four sensors monitoring specific biomarkers: glucose, vitamin C, lactate, and levodopa (a Parkinson’s disease treatment). Sweat moves through microfluidic channels to the sensors, where biomarker levels are analyzed, and energy is harvested.
Seamless Data Transmission and Monitoring
A small chip processes signals from the sensors and transmits data wirelessly via Bluetooth low energy to a custom smartphone or laptop app. “This represents automatic health monitoring right at your fingertips,” said Shichao Ding, a postdoctoral researcher in Wang’s group. “The device can harvest energy and track biomarkers even while the wearer is resting or asleep.”
Future Developments and Customization
In tests, the device tracked various biomarker levels throughout the day—glucose during meals, lactate during exercise and desk work, vitamin C with orange juice, and levodopa after consuming fava beans. Ding and co-author Tamoghna Saha are working on customizing the device to meet individual health needs by detecting different biomarkers. They aim to develop a closed-loop system that not only monitors biomarkers but also administers treatments. For example, a device could continuously monitor glucose levels and automatically deliver insulin for diabetes management, then assess treatment effectiveness by further monitoring.